• 한국태양에너지학회 논문집
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• 제33권6호
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• pp.98-104
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• 2013

At the moment, in Korea, over 90% of energy resources depend on imports, and nearly 60% of electric energy is produced using fossil fuel. Therefore, the government adopted the Climatic Change Convention and has implemented the RPS system since 2012 to actively cope with the dependence on imported energy, and to grow and expand the new renewable energy industry. This study examined the performance results of mandatory supply of solar photovoltaic energy and non-solar photovoltaic energy assigned to providers and the present state after implementation of the RPS system. As a result, the achievement rate in 2012 was 64.7%. Especially, solar photovoltaic energy showed a high achievement rate of 95.7%, whereas non-solar photovoltaic energy showed a low achievement rate of 63.3% due to several problems and was highly dependent on the government. In 2013, the burden of each provider has increased due to more mandatory supply and addition of unfulfilled supply of 2012, and the separate mandatory supply of solar photovoltaic energy established for protection of the solar photovoltaic market is restricting investment. Therefore, there is a need to assign mandatory supply in consideration of the available amount of each new renewable energy.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제26권4호
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• pp.49-57
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• 2020

Purpose: In our country, the aged population accounted for about 13% of the total population in 2018. In addition, it is expected to exceed 20% in 2026, entering an super-aged society. However, the senior welfare housing in Korea currently accommodates only 0.08% of the elderly population, and the increasing amount of the elderly population is very small. Accordingly, this study aims to analyze the causes of supply shortages and to propose directions for revitalizing the supply of welfare housing for the elderly in the private sector. Methods: First, the causes and problems of the poor supply of welfare housing for the elderly were analyzed. Next, the direction was proposed through institutional and case-by-case surveys and expert interviews. Results: It suggested directions such as legal and institutional improvement, inducing the use of REITs, preparing policies to support consumers, allocating a certain percentage of senior welfare housing for the elderly in the reconstruction project, improving awareness of monthly living expenses, and re-discussing sales permits. Implications: Experts said that the direction proposed in this study can have a positive effect on supply activation. However, there were many opinions that re-discussion on permission for sales was necessary due to the excessive impact of the inability to sell. In addition, further research is needed for specific application of the proposed direction.

• 한국융합학회논문지
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• 제12권6호
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• pp.139-150
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• 2021

현재 국내 신재생에너지 보급 정책은 RPS(Renewable Portfolio Standard; 공급의무화제도)이다. 대용량 발전사업자는 신재생 의무공급량을 직접 생산하거나 REC(Renewable Energy Certificates; 공급인증서) 구매를 통해서 확보한다. 정부는 신재생 에너지원의 경제적, 사회적 가치를 평가하여 각 에너지원에 가중치를 매기는 REC 가중치를 여러 차례 개정했으며 의무공급 비율도 점차 증가하도록 개정했다. 본 연구는 정부의 정책이 관련 산업에 미치는 영향을 확인하는 데 도움이 된다. 태양광발전에 관한 REC 가중치 개정과 신재생 의무공급량이 태양광 설비량에 미치는 영향을 분석하기 위해 태양광 설비량을 종속변수로 시계열 분석과 의무공급량에 대한 회귀분석을 수행하였다. 결과적으로 REC 가중치 개정과 의무공급량 증가는 태양광 설비량 증가에 유의미한 영향을 미친다는 것을 확인하였다.

• Journal of the Korean Wood Science and Technology
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• 제35권1호
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• pp.1-10
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• 2007

최근 미국 에너지 시장에서 수송용 바이오연료 생산과 바이오매스자원으로부터의 원료공급 가능성 등에 대하여 조사 연구되었다. 미국의 국가에너지정책의 1차 목표는 수입원유에 대한 의존을 줄이고 다양한 국내자원으로 에너지생산을 증가시키는 것으로 2030년에는 현재 수송용 에너지의 20%를 바이오연료로 대체할 목표이다. 정책적으로 청정공기법령(Clean Air Act), 연방청정연료(Federal Clean Fuel) 프로그램 및 American Jobs Creation Act를 통하여 바이오연료 사용을 증가시키는 노력을 하고 있다. 에너지 원료로서 산림바이오매스는 년간 3억 6800만 dry tons, 농업에서 얻어지는 원료는 현재의 BT기술을 이용한 작물품종 및 경작기술 개발, 농지사용 변화를 기반으로 했을 때 년 간 총 9억 9800만 dry tons이고 이중에서 목질계 바이오매스는 8억 1800만 dry tons이다 현재의 농업상황에서 생산되는 량의 5배에 해당하는 바이오매스 공급가능성이 예측되었다.

• 한국경영과학회지
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• 제38권2호
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• pp.43-63
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• 2013

Remanufacturing is a process of recovering end-of-life products into serviceable parts for producing new products. Due to the limited supply of recovery cores to remanufacture, a remanufacturing firm also needs to produce or procure new parts for fulfilling the demand. This paper is targeted for solving the problem of determining the optimal amount of newly produced and remanufacturing parts, which is called production and remanufacturing planning (PRP) problem, under uncertain supply of recovery cores. The new production mitigates the risk of insufficient core supply while it takes more costs than the remanufacturing. The PRP model in this paper also considers disassemble-to-order (DTO) environment, in which multiple kinds of parts are remanufactured from multiple products on order of the parts. Whereas existing studies presents only heuristic solutions for DTO remanufacturing, this paper provides an exact solution for this problem and analytical sensitivity of the involved cost parameters, adopting multi-dimensional newsvendor modeling and stochastic linear programming techniques. The result shows that production and remanufacturing plans for multiple products are mutually dependent, and a change of cost parameters involved in only one part is propagated to all other parts.

• 경영과학
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• 제31권3호
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• pp.95-111
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• 2014

It is essential to carry out an economic analysis on public water supply projects so that policy makers and water enterprises are aware of the actual value of the project. However, many popular approaches based on discounted cash flow analysis do not capture the uncertainties inherent in cash flow. In order to analyze the economic values of the water supply project of local governments, we utilize real option model, which considers uncertainty in future water price behavior and captures the value of real life flexibility. The real option model is designed to incorporate the option to expand and abandon, and it is applied to a local government case. Furthermore, we assess the project by exploring Luehrman's option space to accommodate the more efficient decision making. The results show that substantial amount of potential value is included in the public water supply service, and the overall value is greater than the value obtained from the discounted cash flow model.

• 한국물환경학회지
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• 제27권2호
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• pp.178-187
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• 2011

National water supply, water resources available, the ratio of water supply to total water resources, and the ratio of water supply to available water resources were investigated to find global seawater desalination plant market for 163 nations. Water resources available per capita from 2007 to 2016, population in water scarcity region from 2011 to 2016, and the ratio of water scarcity population to total population were also analyzed for the countries. Annual percentage increase in total municipal drinking water capital expenditure and Annual percentage increase in total industrial water market were analyzed to predict the amount of water supply by use. 76 countries are suffering from water scarcity and 60 countries among the countries have coastal regions. Forty countries were selected by considering the considerable amount and highly increasing trend of water demand by use. Most countries show increasing trend of industrial water and 82 countries have more than 4% annual increasing rate for domestic water expense from 2008 to 2016 among 163 countries. Among the 76 water scarcity countries 16 countries were finally selected by considering expense prediction by use. Middle-east, east asia, pacific ocean, and west europe regions include most selected countries.

• 대한기계학회논문집B
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• 제33권6호
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• pp.396-402
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• 2009

Recently many efforts have been carried out on the development of energy-efficient and environment-friendly systems in order to preserve natural environment and to reduce environmental loads in the branch of the urban planning and the building design. In this study, a mathematical method was developed and a numerical analysis was carried out with various parameters to provide substantial data for optimal design and operation of urban energy supply systems. Components of the system and their specifications, such as a co-generation system and other heating and cooling systems, could be obtained through this analysis for various resource and energy requirements in urban area. In this study, the system constituents and operating characteristics, and their economic performances such as the value of objective function, the amount of energy consumption were discussed for various load patterns and power load ratios. Also, it turns out that the optimal energy supply system can save energy by $10{\sim}20%$ in comparison with the conventional energy supply system.

• 한국유기농업학회지
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• 제26권3호
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• pp.351-367
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• 2018

This study aimed to analyze socioeconomic effect of eco-friendly free school food supply system by Seoul, which has been consistently extended since 2011. To do so, effect of eco-friendly free school food supply system on the beneficiaries, Seoul citizens, was analyzed by using 'labor & income panel', while that on rural society was analyzed by using the surveys on the eco-friendly agricultural product supply performance by the 'Eco-friendly Agricultural Products Retail Center' as well as for students, school parents, nutrition teachers and nutritionists. The results of analysis showed that eco-friendly school food supply system contributes to income redistribution among the Seoul citizens to a certain extent, provides the eco-friendly agricultural product producers in the rural society with the stable market, and positively influences them to secure stable incomes. In addition, eco-friendly free school food reduced the amount of carbon emissions through the use of environmentally friendly agricultural products resulting in environmental improvements and economic benefits. Considering such effects, free school food supply using the eco-friendly agricultural products needs to be consistently maintained in the future without politic change by political ideology and to be extended to middle school level in medium and short-term.

• 한국산업정보학회논문지
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• 제24권3호
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• pp.31-38
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• 2019

본 연구에서는 그린공급망(green supply chain: gSC) 네트워크 모델이 제안된다. 제안된 gSC 네트워크 모델은 환경적 요인 및 경제적 요인을 고려한다. 환경적 요인으로는 부품 및 제품 수송 과정에서 발생하는 CO2 발생량의 총비용 최소화를 고려하며, 경제적 요인으로는 부품 및 제품 생산처리에 필요한 처리비용, 수송과정에서 발생하는 수송비용, 각 단계에서 고려되는 설비들의 개설을 위한 개설비용의 최소화를 고려한다. 수리모형에서는 환경적 요인 및 경제적 요인을 위해 고려되는 다양한 비용들의 총합의 최소화를 목적함수로 사용하며, 각 단계 간 수송량의 제약 등 다양한 제약조건을 함께 고려한다. 제안된 수리모형의 이행을 위해 유전알고리즘(Genetic algorithm: GA) 접근법을 사용한다. 수치실험에서는 네 가지 규모의 gSC 네트워크 모델을 제시하고, 이를 다양한 수행도 척도들을 사용하여 GA 접근법을 통해 해결하였다. 실험결과는 제안된 gSC 네트워크 모델과 GA 접근법의 우수성을 입증하였다.